Cricothyroidotomy simulation device

ABSTRACT

An artificial anatomical model used in an embodiment as a simulation and training device for performing a cricothyroidotomy procedure on a patient having an upper airway obstruction is provided. Furthermore, the simulation device includes a mandible and neck base structure that geometrically mimicsa human mandible and neck region with corresponding anatomical landmarks such that a cricothyroidotomy procedure can be performed on the device for training purposes in some embodiments. Moreover, various components of the device are easily removable and replaceable independent of one another, further simplifying the training process.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 14/200,466filed on Mar. 7, 2014 which is related to U.S. Provisional Application61/774,090 filed on Mar. 7, 2013. The teachings of this application areincorporated in their entirety and priority to the application isclaimed under 35 USC 119.

BACKGROUND

The subject invention relates to simulation devices provided as teachingaids and for practice of procedures including cricothyroidotomies. Upperairway obstruction is an emergency condition which could result in afatality if the obstruction is not cleared or the airway is not opened.A cricothyroidotomy is an incision made through the skin andcricothyroid membrane to establish a patient airway during certainlife-threatening situations, such as an airway obstruction by a foreignbody, angioedema, or massive facial trauma. Cricothyroidotomy is oftenperformed as a last resort in cases where orotracheal and nasotrachealintubation are impossible or contraindicated. A cricothyroidotomy is aneasier and more quickly performed procedure than a tracheotomy and doesnot require manipulation of the cervical spine. Cricothyroidotomies arealso associated with fewer complications than tracheotomies. In order toproperly perform a cricothyroidotomy under pressure, it is beneficial topractice the procedure beforehand to obtain a level of confidence andknowledge about the procedure and the surrounding anatomy. Medicaltraining such as nursing and medical school training often requirespractice of medical procedures such that once a student completes histraining and enters the medical field, performing these procedures onactual patients carries less risk as a result of the training obtainedand the practice undertaken by the medical professional. The medicalprocedures requiring training and practice include cricothyroidotomyprocedures.

BRIEF DESCRIPTION

For the purposes of promoting an understanding of the principles andoperation of the invention, reference will now be made to theembodiments illustrated in the drawings and specific language will beused to describe the same. It will nevertheless be understood that nolimitation of the scope of the invention is thereby intended, suchalterations and further modifications in the illustrated device, andsuch further applications of the principles of the invention asillustrated therein being contemplated as would normally occur to thoseskilled in the art to which the invention pertains.

FIG. 1 provides a perspective frontal view of an embodiment of anartificial anatomical model of the subject invention useful forcricothyroidotomy or other related training.

FIG. 2 provides a frontal view of an embodiment of an artificialanatomical model including a mandible and neck base structure of thesubject invention with a skin and an optional fat layer removed, andwith a replaceable skin component exposed and placed over a trachealaccess window.

FIG. 3 provides a frontal view of an embodiment of the artificialanatomical model base structure of the subject invention in FIG. 2 withthe replaceable skin component peeled back exposing the hyoid cartilagecomponent through the tracheal access window.

FIG. 4 provides a frontal view of an embodiment of the artificialanatomical model base structure of the subject invention with thetracheal structure partially removed from the model.

FIG. 5 provides a frontal view of an embodiment of the artificialanatomical model base structure of the subject invention with thetracheal structure partially removed from the model, the hyoid cartilagecomponent lifted and the cricoid membrane being removed from thetracheal structure, demonstrating replacement of the cricoid membrane.

FIG. 6 provides a frontal view of an embodiment of the artificialanatomical model base structure of the subject invention wherein thecricoid membrane surrounds the tracheal structure at the trachealopening.

FIG. 7 provides a frontal view of an embodiment of the artificialanatomical model of the subject invention showing the tracheal structureplaced within the model with the replaceable skin component removeddemonstrating the placement of the hyoid bone beneath the mandibleregion of the model.

DETAILED DESCRIPTION

There is much interest in the development of anatomic models withcomponents that simulate those of a human with significant similarityfor use in education, training, and practice of students andprofessionals. More preferably, an anatomic model with easily removableand replaceable anatomic structures is essential to a successful medicallearning environment. The model embodiments of the subject invention mayserve as a highly sophisticated testing and learning system enabling asurgeon or medical student to optimize instrumentation and surgicalapproaches for a particular procedure, particularly a cricothyroidotomy,before having to perform the procedure on a live patient.

In particular embodiments, the subject invention pertains to anatomicmodels that include components that simulate human or non-human animalcomponents of the neck and lower facial (jaw or mandibular) region. Inother embodiments, the invention pertains to anatomic models thatinclude components that simulate human or non-human animal components ofthe head, neck and upper torso region (including any portion between thehead and the clavicle region of the torso). The models may be used fordevelopment, experimentation, or training of students in the medicalfield for procedures performed in practice, or training of persons ofthe general population for emergency situations. Emergency situationsinclude those in which an obstruction to an airway may occur which wouldrequire an emergency cricothyroidotomy or other procedure involving theneck region such as a thyroidostomy or laryngectomy. Because, asdescribed above, a cricothyroidotomy procedure is often performed as alast resort, it is not a procedure that is often practiced. Furthermore,there are few devices which provide the ability to practice acricothyroidotomy procedure having the same anatomical characteristicsas that of a human or non-human animal. Therefore, it has beendiscovered herein a need for a device which allows medical, nursing, andparamedic students as well as the general population to perform trialprocedures on an anatomic model of a human or non-human animal neck andthroat region.

The subject invention would enable a medical or other student tooptimize instrumentation and approaches for a cricothyroidotomy or otherneck-region procedure without putting a patient at risk. Therefore, oneaspect of the subject invention provides an anatomic model or device ofa human or non-human neck and mandibular region including materials thatclosely mimic the physical properties of living tissues. The use of thismodel or device would enable a user to perform trial procedures in anenvironment that closely resembles the patient's anatomy without anyrisk to the patient, or the user. The model or device provided hereinwould therefore allow a user to learn how to perform a particularprocedure before performing it on a patient. The model would beparticularly useful for training procedures for cricothyroidotomies, ina non-limiting example.

Typical engineering materials, including many metals, ceramics, andplastics commonly employed in industry may be used in creating theanatomic model depending on the required analog properties. However, incases where soft tissues are being modeled it will generally beadvantageous to use nonstandard materials such as hydrogels. Thesematerials swell in the presence of moisture and can retain large amountsof water without dissolving. They are constructed of one or morehydrophilic polymer molecules, although copolymerization withhydrophobic monomers may also lead to the formation of a hydrogel. Thesematerials are generally elastic, and exhibit a three-dimensional networkthat is either crosslinked directly by chemical bonds or indirectlythrough cohesive forces such as ionic or hydrogen bonding. Hydrogels areparticularly advantageous in this application because the formula may bemanipulated to give a combination of water content, lubricity, abrasionresistance, and other properties characteristic of living soft tissues.In this respect, these materials are particularly suited to modelingtissues such as fat or muscular tissues in addition to skin tissues.Hydrogels also provide an ideal substrate for maintaining a surface oflive cells if so desired.

In exemplary embodiments, the models or devices comprise structures suchas muscles, skin layers, and/or fat layers that are made of hydrogelmaterials. The models provide an effective teaching and training device,due to their similarity to real tissues, organs, and organ systems, aswell as the simplicity in the replacement of parts or components whichmay be damaged or used during the training. In certain embodiments, thecomponents of the anatomic models are replaceable independently of oneanother, providing a substantial cost-saving feature over currentteaching devices in the field which require replacement of an entireteaching model or costly, larger portions of the model.

One important feature of certain embodiments of the subject invention isthe implementation of synthetic materials that can simulate one or morephysical properties of living tissues. These materials are in most casesthe hydrogel materials that are designed on the basis of physical testsperformed on actual living target tissues. For example, a particularanalog material might be designed to exhibit a tensile strength close to10 kPa to mimic a target tissue that exhibits a tensile strength of 10kPa. One or more components made from these materials are then assembledinto a configuration that mimics both the size and geometry of thetarget anatomic structure.

The models of the subject invention may employ a wide variety ofhydrogel materials, including but not limited to polyvinyl alcohol,polyvinyl pyrrolidone, polyethylene oxide, polyhydroxyethylmethacrylate; polyethylene glycol, hyaluronic acid, gelatin, carrageen,alginates, chondroitan sulfate, dermatan sulfate (and otherproteoglycans). This entire class of materials is physically moretissue-like simply by nature of incorporating water, but by carefullycontrolling such parameters as molecular structure, density, wallthickness, durometer, and many other physical properties andcharacteristics a good match between the actual tissue and analogmaterial may be achieved.

Poly (vinyl alcohol) is normally produced by the acid-catalyzedhydrolysis of poly (vinyl acetate), which effectively converts thependant acetate groups to hydroxyl groups. The properties of theresulting polymer are determined by tacticity, degree of hydrolysis, andmolecular weight. Most commercial grades of PVA are stereoregular(primarily isotactic) with less than 2% of the repeat units forming inthe ‘head-to-head’ (adjacent hydroxyl groups) configuration. In theory,this should allow a high degree of crystallinity in the finishedproduct. However, this is hindered by the presence of residual acetategroups so the tendency toward crystallization depends primarily on thedegree of hydrolysis. This refers to the percentage of converted acetategroups on the main chain. Partially hydrolyzed grades (less than 75%conversion) do not crystallize significantly and are soluble in water atroom temperature. This is because the large number of bulky acetategroups increases free volume and prevents the long-range interchainassociations required for crystallization to occur. As the degree ofhydrolysis increases the loss of bulky acetate groups reduces freevolume and the chains are allowed to more closely approach one another.The compact but highly polar hydroxyl groups then come into closeproximity and ‘bind’ the chains together through strong hydrogenbonding. These interchain forces increase the degree of crystallinityand greatly reduce solubility. In fact, in spite of the highconcentration of hydroxyl groups completely hydrolyzed grades of PVAshould be heated to nearly 100 C to attain solution. These materialsexhibit excellent mechanical properties and chemical resistance and alsoswell to a significant degree.

The properties of PVA hydrogels vary with molecular weight, but sincethese materials are normally obtained in polymer form the molecularweight cannot easily be adjusted. Instead these properties are typicallymodified by means of chemical or physical crosslinking. Chemical gelsare easily formed by the addition of agents which undergo condensationwith the hydroxyl groups on the main chain. A number of aldehydes(glutaraldehyde, formaldehyde, etc.), dicarboxylic acids (adipic acid,terephthalic acid, etc.), and metal ions (Fe³⁺, B⁵⁺, etc.) will formchemical bonds with PVA which result in crosslinks. Longer moleculessuch as diacids are generally preferred over metal ions because the ion‘bridge’ is short and restrictive, embrittling the material. Moleculessuch as adipic acid can effectively restrict chain mobility whilemaintaining some measure of flexibility.

The orientation of a given gel material may be induced by drawing thematerial, by heat treatment, or by casting the polymer in solution witha gelling agent. These agents create specific interactions between thehydroxyl groups on adjacent chains, bringing them together to improvehydrogel bonding. Many such agents are known, and this process is easilyemployed on a laboratory scale.

The models of the subject invention are characterized by a similarity ofgeometry, of individual component physical properties, and ofcomponent-to-component interfacial properties with living tissue. On thesimplest level, individual model components are fabricated such thatthey mimic the geometry of a particular target anatomy.

The geometric data needed for fabrication is typically obtained in twoways. The traditional approach is to obtain data from the literature onmorphology or from cadaver measurements. While not a bad approximation,this method is time-consuming and permits a large degree of error. Abetter method would be to obtain the geometric data directly from apatient.

After collecting the appropriate geometric data, the individual modelcomponents may be fabricated from appropriate analog materials.Depending on the complexity of the part and the type of materials used,the individual component might be molded, extruded, or machined. Themodels of the subject invention are constructed from multiplecomponents, and these individual components are fabricated in such a waythat they mimic the geometry (length, width, diameter, thickness,cross-section, shape, etc) of a particular portion of the targetanatomy.

The individual components of the subject invention are assembled in sucha way that the interaction between adjacent components yields theoverall interaction expected in the actual target tissue. That is, theinterfacial properties (bond strength, component-to-component friction,etc) between the various model components are designed to simulate theinteraction between the relevant tissues in the target anatomy.

In one embodiment, an artificial anatomical model useful forcricothyroidotomy training including a mandible and neck base structurethat geometrically mimics at least a portion of a human or non-humananimal mandible and neck region extending from the mandible (ormandibular portion) to the inferior portion of the neck is provided. Atleast a portion of the mandible and neck base structure may be comprisedof, at least in part, a muscle portion, and a skin layer may be disposedover the muscle portion in an embodiment. The base structure includes atracheal access window.

The model may include a mounting base, and at least a portion of themandible and neck may include a muscle portion, wherein the muscleportion is comprised of, in part or in whole, a hydrogel, wherein themuscle portion geometrically mimics at least a portion of a human ornon-human animal muscular tissue and simulates at least onepredetermined physical characteristic of said muscle possessing human ornon-human animal muscular tissue with at least fifty percent or moresimilarity, in one embodiment. The muscle portion may include an openingin the center portion of the neck region defining the tracheal accesswindow in the base structure. The model may further include a skin layerand optionally a fat layer disposed over the muscle portion, wherein thefat layer is disposed under the skin layer, in an embodiment. The skinlayer, fat layer, or skin and fat layer is comprised of, in part or inwhole, a hydrogel, wherein the skin and/or fat layers geometricallymimic at least a portion of a human or non-human animal skin and/or fattissue, respectively, and simulate at least one predetermined physicalcharacteristic of the skin and fat possessing human or non-human animalskin and/or fat tissue with at least fifty percent or more similarity,in one embodiment. The skin and/or fat layer may include a small skinand/or fat layer opening in the center portion of the neck region whichsuperimposes a portion of the tracheal access window, in an embodiment,and through which at least a portion of a replaceable skin component canbe seen.

The at least one predetermined physical characteristic of muscle tissue,fat layer and/or skin layer comprises at least one of the following:color, tensile modulus, shear strength, puncture resistance, compressivemodulus, dielectric constant, electrical conductivity, and/or thermalconductivity, in some embodiments.

Furthermore, the model may include a tracheal structure disposed withinand removable from the base structure, wherein a portion of the trachealstructure is covered by the muscle portion such that a small portion ofthe tracheal structure is revealed through the tracheal access windowdefined in the muscle portion of the base structure in one embodiment.The tracheal structure comprises a tracheal aperture which is alignedwith the tracheal access window of the base structure in an embodiment.A first end of the tracheal structure may be connected to the mountingbase. A removable cricoid membrane may surround and be removable from atleast a portion of the tracheal structure at the tracheal aperture. Inone embodiment, the cricoid membrane covers the tracheal aperture.

A further embodiment includes a hyoid cartilage component affixed atleast at one end to the tracheal structure and disposed ventral to theremovable cricoid membrane, the hyoid cartilage component having a hyoidopening and being associated with a hyoid bone. The embodiment furtherincludes a replaceable skin component which may be disposed over thebase structure at the tracheal access window, but ventral to the hyoidcartilage component. The skin and/or fat layer may be disposed ventralto the replaceable skin component, such that the replaceable skincomponent is visible through a skin and/or fat layer opening, in oneembodiment. In another embodiment, the model may not include thereplaceable skin component, wherein the skin layer is disposed ventralto the tracheal access window and the muscle portion. Once an incisionhas been made in the skin and/or fat layer, the replaceable skincomponent may be used to cover over the tracheal access window forsubsequent uses of the model. Thereafter, the incision can be made inthe replaceable skin component. After the first use of the model, a skinand/or fat layer opening can be made in the skin and/or fat layer,wherein the opening is aligned with the tracheal access window such thatfor subsequent trainings, an incision can be made in the portion of thereplaceable skin component which appears through the skin and/or fatlayer opening.

In a further embodiment, the cricoid membrane can be secured to thetracheal structure. The cricoid membrane may be secured with any type offastener known to those of skill in the art. In one particularembodiment, for example, the cricoid membrane may be secured to thetracheal structure with one or more ring clips.

In a further embodiment, the components of the model including thetracheal structure, the cricoid membrane, and the replaceable skincomponent, are independently removable and replaceable of one another.Optionally, the skin and/or fat layers, and the muscle portions areindependently removable and replaceable of one another. Furthermore, thehyoid cartilage component is optionally removable and replaceableindependent of the other components of the model. The trachealstructure, cricoid membrane, hyoid cartilage, and the replaceable skincomponent are comprised of tissue analog materials, in one embodiment.

The subject device provides for easy set up and replacement of thevarious components, wherein the only two components which would requirereplacement after each use, in an embodiment, include the replaceableskin component in the center of the neck portion and the cricoidmembrane on the tracheal structure.

In a further embodiment, a method of conducting a cricothyrotomyprocedure on a model is provided. The method includes obtaining theartificial anatomical model useful for cricothyroidotomy training asdescribed herein, and cutting the replaceable skin component and cricoidmembrane at a location adjacent to the tracheal aperture whereby anairway incision is made through the replaceable skin component and thereplaceable cricoid membrane in the tracheal structure, in anembodiment. This incision can be made in the replaceable skin componentand the replaceable cricoid membrane through the hyoid opening, forexample, between the hyoid bone and the hyoid cartilage component.Following the incision, an air tube can be inserted into the airwayincision.

In a further embodiment, a method of reloading a cricothyroidotomy modelfor subsequent training usage, the model comprising (a) a mandible andneck base structure that geometrically mimics at least a portion of themandible and neck comprised of, at least in part, a muscle portion, anda skin layer disposed over the muscle portion, the base structuredefining a tracheal access window; (b) a tracheal structure disposedwithin and removable from the base structure; the tracheal structurecomprises a tracheal aperture that is aligned with the tracheal accesswindow, (c) a replaceable cricoid membrane surrounding the trachealstructure at the tracheal opening; (d) a hyoid cartilage componentcomprising a hyoid opening, wherein the hyoid cartilage component isaffixed at one end to a hyoid bone and/or the tracheal structure anddisposed ventral to the cricoid membrane; and (e) a replaceable skincomponent disposed over the base structure at the tracheal access windowbut ventral to the hyoid cartilage component. The method includesremoving at least in part the skin layer from the muscle portion, andremoving the replaceable skin component. The method further includeslifting the hyoid cartilage component, removing the cricoid membranefrom the tracheal structure, and putting a replacement cricoid membraneonto the tracheal structure, and securing the cricoid membrane to thetracheal structure. The method includes laying the hyoid cartilagecomponent down over the cricoid membrane. The method includes putting areplacement skin component over the tracheal structure above the hyoidcartilage component, and returning the skin layer over the muscleportion whereby the tracheal access window is aligned with a portion ofthe replacement skin component, in an embodiment.

Turning to the FIGS, FIG. 1 provides a perspective frontal view of anembodiment of an artificial anatomical model 100 of the subjectinvention, wherein the skin layer 16 can be seen as placed over the neckregion 14 and mandible region 12 of the model 100. The skin layer 16 mayinclude a fat layer disposed beneath it. One or more layers of skinand/or fat may be provided. A skin layer opening 18 is provided, suchthat a portion of a replaceable skin component 20 can be seen throughthe skin layer opening 18. The anatomical model 100 may be mounted on amounting base 10 as shown in FIG. 1. Once a user has used the model toperform a procedure, the skin window 20 can be shifted such that anyopenings created in the skin window 20 do not appear through the opening18 in preparation for a future procedure. Alternatively, the skin window20 can be removed from the model 100 and replaced entirely.

FIG. 2 provides a frontal view of an embodiment of an artificialanatomical model 100 of the subject invention with the skin layer 16removed, revealing a muscle portion 22 underneath. The replaceable skincomponent 20 is exposed and placed over a tracheal access window 26(tracheal access window 26 is shown in FIG. 3). A tracheal structure 24can be seen emerging from a lower portion of the model 100.

FIG. 3 provides a frontal view of an embodiment of the artificialanatomical model 100 of the subject invention as shown in FIG. 2 withthe replaceable skin component 20 peeled back exposing a hyoid cartilagecomponent 28 through the tracheal access window 26. A hyoid bone 36 isvisible through the tracheal access window 26 in FIG. 3, positionedbeneath the mandible region of the model. In the embodiment shownherein, a hyoid opening 29 is shown between the hyoid bone 36 and thehyoid cartilage component 28. This hyoid opening 29 is created, in oneexample, as a space between the hyoid cartilage component 28 and thehyoid bone 26, wherein a first portion and a second portion of the hyoidcartilage component 28 is associated with the hyoid bone 29, leaving agap (hyoid opening 29) in the center. Through the hyoid opening 29, acricoid membrane 30 (shown in FIG. 4) can be seen.

FIG. 4 provides a frontal view of an embodiment of the artificialanatomical model 100 of the subject invention wherein the trachealstructure 24 is partially removed from the model 100. A portion of thetracheal structure 24 is shown as surrounded by a cricoid membrane 30,and the hyoid cartilage component 28 is disposed over the cricoidmembrane 30. The cricoid membrane 30 is attached to the trachealstructure 24 by ring clips 34 in the embodiment shown. Two ring clips 34are shown in the embodiment of FIG. 4, one disposed on either side of atracheal opening 32 (shown in FIG. 5), however, one ring clip 34 may beused to affix the cricoid membrane 30 to the tracheal structure 24, inother embodiments, or other means for attachment of the cricoid membranemay also be used in addition to or in place of the ring clips 34 shownherein. FIG. 5 provides a frontal view of an embodiment of theartificial anatomical model 100 of the subject invention with thetracheal structure 24 partially removed from the model 100, the hyoidcartilage component 28 lifted from the tracheal structure 24 and thecricoid membrane 30 partially removed from the tracheal structure 24revealing a tracheal opening 32. FIG. 5 shows a process of removal oradjustment of the position of the cricoid membrane 30 from the trachealopening 32 by releasing the ring clips 34. Once the cricoid membrane 30is removed from the tracheal structure 24, the membrane 30 can bereplaced with a new cricoid membrane 30. Alternatively, once the cricoidmembrane 30 has been used (i.e., an incision has been made therethrough), it can be used again by adjusting the cricoid membrane 30 bysliding it into a position enabling a new cut and/or puncture at or nearthe tracheal opening 32 to occur.

FIG. 6 provides a frontal view of an embodiment of the artificialanatomical model 100 of the subject invention wherein the cricoidmembrane 30 surrounds the tracheal structure 24 at the tracheal opening32, and two ring clips 34 are used to secure the cricoid membrane 30onto the tracheal structure 24. The hyoid cartilage component 28 hasbeen lifted in the view of FIG. 6 to reveal the components of the deviceunderneath the hyoid cartilage component 28. Once the cricoid membrane30 is removed from the tracheal structure 24, the tracheal structure 24can be re-inserted into the model 100 beneath the muscle portion 22. Ina further embodiment, a portion of the tracheal structure 24 may beattached or affixed to the mounting base 10. Other components of themodel 100 may be attached to the mounting base 10 in varyingembodiments.

FIG. 7 provides a frontal view of an embodiment of the artificialanatomical model 100 of the subject invention showing the trachealstructure 24 placed within the model 100 with the replaceable skincomponent 20 removed (replaceable skin component not shown in FIG. 7)demonstrating the proper placement of the tracheal structure 24, suchthat the hyoid bone 36 is positioned beneath the mandible region 12 ofthe model 100. The cricoid membrane 30 can be seen between the hyoidbone 36 and the hyoid cartilage component 28 through the hyoid opening29.

The terms “anatomic(al) model”, “anatomic(al) device”, and “modeltraining device” are used interchangeably, herein. The term“hydrogel(s)” as used herein refers to a unique class of materials thatcontain a large amount of water and generally exhibit a high degree ofelasticity and lubricity. These materials are ideal for simulating thephysical properties of many living soft tissues. Hydrogels are materialsthat are wetable and swell in the presence of moisture and retain waterwithout dissolving. These materials are generally constructed of one ormore hydrophilic polymer molecules, although copolymerization withhydrophobic monomers may also lead to the formation of a hydrogel. Thesematerials are generally elastic, and exhibit a three-dimensional networkthat is either cross linked directly by chemical bonds or indirectlythrough cohesive forces such as ionic or hydrogen bonding.

The tissues and structures that “are comprised of, in part or in whole,a hydrogel,” aside from hydrogel materials, may include, but are notlimited to, hydrophilic polymers, interpenetrating orsemi-interpenetrating polymer networks, fibers, silicone rubber, naturalrubber, other thermosetting elastomers, other thermoplastic elastomers,acrylic polymers, other plastics, ceramics, cements, wood, Styrofoam,metals, actual human tissues, actual animal tissues, and any combinationthereof. For model embodiments comprising one or more components, eachcomponent part may be constructed from one or more tissue analogmaterials.

The muscle portion(s), skin layer(s), fat layer(s), and bone(s)(including the tracheal structure) are formulated to simulate one ormore physical characteristics of a target living tissue. These physicalcharacteristics include, but are not limited to, uni-axial ormulti-axial tensile strength or modulus, uni-axial or multi-axialcompressive strength or modulus, shear strength or modulus, coefficientof static or dynamic friction; surface tension; elasticity; wettability;water content; electrical resistance and conductivity; dielectricproperties; optical absorption or transmission, thermal conductivity,porosity, moisture vapor transmission rate, chemical absorption oradsorption; or combinations thereof. Each tissue or structure isdesigned so that one or more of its physical characteristics willsufficiently match the corresponding physical characteristic(s) of therelevant tissue on which the muscle portions, skin layers, fat layers,and bones is based. More specifically, each tissue analog material ispreferably formulated so that the physical characteristic(s) of thetissue analog fall within a range that is no more than 50% lesser orgreater than the targeted physical characteristic(s) of the relevantliving tissue on which the tissue analog material is based.

The term “artificial” as used herein to describe an anatomic modelrefers to a model that is either synthetically manufactured or naturallymanufactured in vivo and assembled with model components. The anatomicmodel includes model components such as, muscle portion, ligamentstructures, tendons, bones, skin, fat, and other such structures or“components.” In the case of naturally manufactured artificialcomponents, this may refer to actual tissues or anatomical structuresprocured from a cadaveric human or from a nonhuman subject that areremoved from the subject processed and assembled with other artificialcomponents.

The term “geometrically mimic” as used herein refers to a comparativerelationship of a configuration of an artificial anatomical model,and/or artificial structural component thereof, with a target anatomicalstructure wherein such configuration comprises one or more similargeometric features of the target anatomical structure to be mimicked,such as length, width, diameter, thickness, cross-section, and/or, inmost cases general shape of a particular target anatomical structure.

The term “human or non-human animal tissue” as used herein refers to theone or more tissues that constitute a human or non-human animalanatomical structure. “Anatomic structures” may include tissue types,bone types, organ types, and/or part of organ(s).

As used herein the term “human or non-human animal anatomical structure”refers to one or more tissue structural components that make up a partof anatomy of a human or non-human animal. A part of anatomy mayinclude, but is not limited to, whole organs, parts of an organ, or asection of a body comprising one or more tissue types, organ types,and/or part of organ(s).

As used herein, the terms “tracheal opening” and “tracheal aperture” canbe used interchangeably.

It is important to an understanding of the present invention to notethat all technical and scientific terms used herein, unless definedherein, are intended to have the same meaning as commonly understood byone of ordinary skill in the art. The techniques employed herein arealso those that are known to one of ordinary skill in the art, unlessstated otherwise. For purposes of more clearly facilitating anunderstanding the invention as disclosed and claimed herein, thefollowing definitions are provided.

While a number of embodiments of the present invention have been shownand described herein in the present context, such embodiments areprovided by way of example only, and not of limitation. Numerousvariations, changes and substitutions will occur to those of skill inthe art without materially departing from the invention herein. Forexample, the present invention need not be limited to best modedisclosed herein, since other applications can equally benefit from theteachings of the present invention. Also, in the claims,means-plus-function and step-plus-function clauses are intended to coverthe structures and acts, respectively, described herein as performingthe recited function and not only structural equivalents or actequivalents, but also equivalent structures or equivalent acts,respectively. Accordingly, all such modifications are intended to beincluded within the scope of this invention as defined in the followingclaims, in accordance with relevant law as to their interpretation.

What is claimed is:
 1. An artificial anatomical model useful forcricothyroidotomy training, comprising: a mandible and neck basestructure that geometrically mimics at least a portion of the mandibleand neck of a human or non-human animal comprised of, at least in part,a muscle portion, wherein said base structure comprises an opening in acenter portion of the neck region, said opening defining a trachealaccess window in said muscle portion; a tracheal structure disposedwithin and removable from the base structure, said tracheal structurecomprises a tracheal aperture, wherein at least a portion of thetracheal aperture is aligned with the tracheal access window, wherein aportion of the tracheal structure is covered by the muscle portion suchthat a portion of the tracheal structure is aligned with the trachealaccess window; a replaceable cricoid membrane surrounding the trachealstructure at the tracheal aperture; a hyoid cartilage component affixedat one end to the tracheal structure and/or a hyoid bone and disposedventral to the cricoid membrane; and a replaceable skin componentdisposed over the base structure at the tracheal access window butventral to the hyoid cartilage component.
 2. The model of claim 1,further comprising a skin layer disposed over at least a portion of themuscle portion, ventral to the replaceable skin component.
 3. The modelof claim 2, wherein the skin layer comprises at least one skin layeropening which superimposes a portion of the tracheal access window, suchthat when the skin layer is disposed over the base structure, at least aportion of the replaceable skin component is visible through the atleast one skin layer opening.
 4. The model of claim 2, wherein the skinlayer is comprised of, in part or in whole, a hydrogel, said skin layergeometrically mimics at least a portion of a human or non-human animalskin tissue and simulates at least one predetermined physicalcharacteristic of said skin possessing human or non-human animal skintissue with at least fifty percent or more similarity.
 5. The model ofclaim 1, wherein at least one predetermined physical characteristic ofthe replaceable skin component or cricoid membrane comprises at leastone of the following: color, tensile modulus, shear strength, punctureresistance, compressive modulus, dielectric constant, electricalconductivity, and/or thermal conductivity.
 6. The model of claim 1,wherein the tracheal structure, the cricoid membrane, and thereplaceable skin component, are independently removable and replaceableof one another.
 7. The model of claim 1, wherein the tracheal structure,the cricoid membrane, and the replaceable skin component, are comprisedof tissue analog materials.
 8. The model of claim 1, further comprisinga fat layer, wherein said fat layer is disposed over at least a portionof the muscle portion.
 9. The model of claim 2, further comprising a fatlayer ventral to the replaceable skin component, and under the skinlayer.
 10. The model of claim 9, wherein the fat is comprised of, inpart or in whole, a hydrogel, said fat layer geometrically mimics atleast a portion of a human or non-human animal fat tissue and simulatesat least one predetermined physical characteristic of said fatpossessing human or non-human animal fat tissue with at least fiftypercent or more similarity, wherein said fat layer comprises a small fatlayer opening which superimposes a portion of the tracheal accesswindow.
 11. The model of claim 1, wherein the model is associated with amounting base.
 12. The model of claim 6, wherein a portion of thetracheal structure is connected to the mounting base.
 13. The model ofclaim 1 wherein the cricoid membrane is secured to the trachealstructure.
 14. The model of claim 13, wherein the cricoid membrane issecured with one or more ring clips.
 15. The model of claim 1, whereinthe muscle portion is comprised of, in part or in whole, a hydrogel,said muscle portion geometrically mimics at least a portion of a humanor non-human animal muscular tissue and simulates at least onepredetermined physical characteristic of said muscle possessing human ornon-human animal muscular tissue with at least fifty percent or moresimilarity,
 16. A method of conducting a cricothyroidotomy procedure ona model comprising; obtaining the model of claim 1; and cutting saidreplaceable skin component and cricoid membrane at a location adjacentto said tracheal aperture; whereby an airway incision is made in themodel.
 17. A method of reloading a cricothyroidotomy model forsubsequent training usage, the model comprising (a) a mandible and neckbase structure that geometrically mimics at least a portion of themandible and neck comprised of, at least in part, a muscle portion, anda skin layer disposed over said muscle portion, said base structuredefining a tracheal access window; (b) a tracheal structure disposedwithin and removable from the base structure; said tracheal structurecomprises a tracheal aperture that is aligned with the tracheal accesswindow, (c) a replaceable cricoid membrane surrounding the trachealstructure at the tracheal opening; (d) a hyoid cartilage componentaffixed at one end to the tracheal structure and disposed ventral to thecricoid membrane; and (e) a replaceable skin component disposed over thebase structure at the tracheal access window but ventral to the hyoidcartilage component wherein the method comprises removing at least inpart the skin layer from the muscle portion; removing said replaceableskin component; removing said cricoid membrane from said trachealstructure; putting a replacement cricoid membrane onto said trachealstructure; putting a replacement skin component over said trachealstructure above said cricoid membrane; and returning said skin layerover said muscle portion whereby said tracheal access window is alignedwith a portion of said replaceable skin component.
 18. The method ofclaim 17, further comprising displacing the hyoid cartilage componentfrom the cricoid membrane prior to removing the cricoid membrane fromthe tracheal structure.
 19. The method of claim 18, further comprisingrepositioning the hyoid cartilage component is over at least a portionof the replacement cricoid membrane and under at least a portion of thereplacement skin component.